This invention relates to water fountains and an associated programmable controller for generating dynamically changing flow patterns.
Current indoor water fountains especially those intended for tabletop use generally have a preset flow rate and one or more outlets to channel water over the fountain elements. These fountains are non-dynamic and have a fixed flow pattern.
Virtually all indoor fountains employ a low power alternating current submersible pump. These pumps are generally comprised of a single-phase permanent-magnet synchronous motor (PMSM) with a multi-pole permanent-magnet rotor and a coupled impeller. Such pumps normally have no directional preference and are characterized by having notoriously low start-up torque. In order to overcome the low start-up torque problem and attain a pump with reliable starting characteristics, impellers have been designed with flexible blades and with mechanical slip-clutch arrangements to allow the rotor to begin rotation without having to overcome the water resistance of the impeller. These slip-clutch arrangements allow the impeller to rotate freely for a portion of one revolution before engaging a stop that prevents further rotation of the impeller relative to the rotor. Even with these modifications the majority of such pumps do not reliably start which is unfortunate in a fountain application. Pump and impeller apparatus with the above characteristics have been taught by Cabalcante (U.S. Pat. No. 4,247,265), Ellis, et al (U.S. Pat. No.5,282,961) and Willinger and Ivasauskas (U.S. Pat. No. 4,861,468). These and functionally similar pumps are used extensively worldwide both in small fountain and aquarium applications.
A number of large-scale fountains with dynamic elements primarily designed for outside use has been reported. Owing to the method of water distribution and control, these are generally quite expensive to implement. Alba (U.S. Pat. No. 5,069,387) teaches a fountain with a multiplicity of nozzles with valves that are controlled by a microprocessor to vary flow rates. Chikazumi (U.S. Pat. No. 5,288,018) teaches a fountain with valves that are turned on and off by a controller to produce a variation of flows over a fountain wall. Dach (U.S. Pat. No. 5,439,170) teaches a fountain with a plurality of nozzles and valves that are turned off and on by a computer to produce various ornamental effects. Fuller and Robinson (U.S. Pat. No. 4,892,250) teach dynamic fountains with a number of computer controlled proportional valves feeding a number of nozzles. Przystawik (U.S. Pat. No. 4,269,352) teaches a dynamic fountain with a plurality of nozzles linked to pumps that are selectively turned on and off by electrical circuitry. None of these control the flow rate to the fountain elements by varying the flow rate of the individual pumps.
Various attempts to make fountains with changeable lighting have been reported. Evans (U.S. Pat. No. 305,117) teaches a fountain illuminated by a color blending system that responds to variations in amplitude and frequency of a music signal. Chikazumi (U.S. Pat. No. 5,288,018) reports a fountain with rear disposed lighting modules whose intensity can be selectively varied. Dach (U.S. Pat. No. 5,439,170) teaches a plurality of lamps that can be varied in response to music. While controlling fountain lighting, none of these inventions effect a variation in individual nozzle output proportional to the amplitude or frequency of the input sounds.
It is a primary objective of this invention to provide a programmable controller for varying the flow rate of the fountain in a predetermined manner by varying the flow rate of a pump so as to generate dynamically changing flow patterns.
It is a related object of this invention to provide a variation in the flow rate of water to a fountain element by simultaneously changing the frequency and pulse width of an alternating current (AC) input to an alternating current permanent-magnet synchronous motor pump in such a manner that the motor""s power requirements are met over as wide a speed range as possible.
It is a related object of this invention to provide a programmable fountain pump control for generating a predetermined multiplicity of sequential flow volumes to a fountain so as to generate changeable water flow patterns over time.
It is a related object of this invention to provide a programmable pump control coupled with a rigidly connected rotor and impeller assembly that will repeatably and reliably start and will operate without impeller chatter.
It is a related object of this invention to provide a microprocessor driven control to vary the output of a low voltage AC PMSM in a predetermined manner.
It is a related object of this invention to provide a pump control that varies pump output in response to changes in the ambient sound level, to changes in an external audio signal and to changes in an external data input/output signal.
These and other objects of the invention are met by a programmable fountain controller for varying the flow rate of a fountain pump in a predetermined manner, wherein the mode of operation is selected from a group comprising a programmed mode, an audio input mode, a manual mode and an external data input/output mode.